ClinVar Genomic variation as it relates to human health

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease.

STK11:c.615G>A p.(Ala205=) variant was detected in 2 patients without Peutz-Jeghers phenotype. The variants is predicted to create a new acceptor splice site by in silico splicing tools. Functional RNA study has shown that the variant causes insignificant splicing aberration (PMID: 34439939). Therefore the variant was classified as likely benign (ACMG/AMP: BS3, BP5, PM2).

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign.

This variant is considered benign. This variant is a silent/synonymous amino acid change and it is not expected to impact splicing.

The STK11 p.Ala205= variant was identified in 1 of 14102 proband chromosomes (frequency: 0.00007) from individuals or families with breast cancer and was not identified in 22482 control chromosomes from healthy individuals (Momozawa, 2018). The variant was also identified in dbSNP (ID: rs532889728) as “With other allele”, ClinVar (classified as benign by GeneDx, as likely benign by Ambry Genetics and Counsyl, and as uncertain significance by Invitae and Color Genomics), LOVD 3.0 (classified as uncertain significance). The variant was identified in control databases in 10 of 238092 chromosomes at a frequency of 0.000042 (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: Latino in 2 of 30902 chromosomes (freq: 0.000065), European Non-Finnish in 6 of 105662 chromosomes (freq: 0.000057), East Asian in 2 of 16486 chromosomes (freq: 0.0001), while the variant was not observed in the African, Other, Ashkenazi Jewish, European Finnish, and South Asian populations. The variant has been observed in our laboratory in a patient with pancreatic cancer with an alternate molecular basis for disease (ATM c.1A>G). In a study of STK11 variants this variant was observed to demonstrate IHC stain intensity comparable to wild type (Pelak, 2013). The p.Ala205= variant is not expected to have clinical significance because it does not result in a change of amino acid and is not located in a known consensus splice site. The variant occurs outside of the splicing consensus sequence and 3 of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) predict a greater than 10% difference in splicing; however, this information is not predictive enough to assume pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time although we would lean towards a more benign role for this variant. This variant is classified as likely benign.